Router bit



Patented Mayer i927;

RAYAIL. CARTER, or PHOENIX, rNEW Scolari.V

, ROUTER BIT.

Application filed October 28, i926.' Serial No. 144,807. di

This invention relates to a new and vuseful vimprovement in routing'bits, and'has for its object to provide a rotary tool of the tluted type, having 'la 1 plurality of` longitudinal ridges and grooves the ridges being formed with side cutting edgesV Tlieprimary Lob,- ,ject is to provide a'bit of the character, wherein-the several cutting edges are correspondingly reduced to less than one-half their normal length as` compared with the 'olderqbits of this class..l A further object ,is to dispose these relatively narrow cutting {i2/.is atop end view of the same. Fig. 3

i drawing, in which'- j edges in suc-h manner that'each edge travels driven, more/evenly throughout the lengthV ofthe bit, and eliminating chattering, vin bratinw and noise common ,to tinted router land planer' bits in Common use.

I attain these` objects by the means' set Vforth in tliedetailed descriptionwhich fol-v ows, `and lasilliistrated by lthe acompanying Figure 1 'is a bottom'end vewfofa bit formed with three side cutting ridges. Fig.

is a view, showing a front side elevation of Athe lowermostcutting `blade.- Fig. 4f isf a similar view, showing a'full side elevation ofthe inedial"'cutting blade. Fig. Aisa similar view, showing a full side, elevation i Vof the. top cuttingfblade. The last three views show the sequential Vp'erfori'nance of "the several blades, and the respect-ive planes in which the Asaid blades perform their cut-V ting work, While passing a given point, asv

' indicated by the broken'v'er-tical line A-A in Fig. 3. And Figs. aiid' arebizokenV elevations, showing modified cuttingfblades In thedrawing, ,2 represents the-main body or shank of the bit,'which is 'preferably a solid cylinder adapted-to be supported and` driven i suitable `chuck/(not shown). The lower "end portion*A off the shank 2 is 'preferablyz enlarged, v aiidthis "portion is also luted, asat 3,.fo r providing a plurality of angular longitudinal ridges,

4, 5 and', each of said ridges in order, from the bottom to thel top of the enlargement b eing milled .or cut "away'at different points* proper.share of the cuttiiw as at'rL, 5'., and y6', for reducing saidnportions and proyiding similar projecting radial. primary cutting blades orf edges, 4&-512-62, y

said4V reduced portions @having relatively :sharp secondary cuttingedge/sf?,` arranged respectively in the sainey l vertical planes 'as the primary bladesf. These secondary edges rarely perform any actual cutting',"butfare `useful for strengthening the cutting' end of the bit,'as well as forejecting the' chips vresulting from the. cutting byther primary y blades. The blades ta-ft are preferably disposed in parallel planes horizontally according to the drawing, so thateach blade Y Vcuts a path of `its own when the bitis rotated. The primary blades are substantiallyA the same length, and they taper from-"end to end circumferentially for. enablingtheir sharpedges to effect freeand clear '.cuttiiig. 'The said blades yare also backed Voff eccentric to the axis ofthe shank 2, forpreventing -chokingrof the bit during routing or other work. The V`vcutting edges of the 'primary 'blades are preferably of such kbreadth that each blade tends to cut a pathl that slightly' overlaps the path ofthe adjacent blade,fthere` by ensuring the complete and perfect routingl of anyjob, in case'thecorners of either of the blades become dulled or broken. The .primary blade '43 is disposed at the extreme cutting vedge preferably eXtendsbelow` the .a5 'y Vlower 'end 'ofthe rib 4:, and a portion of its plane of the? bottom Vof the shanlg'and is,

aadpted to bore or lcut endwi'se for sinking the tool axiallyto Athe projlier depth. The

" ridges laandY v6 Vare Asubstantially level-or 1 flushr with the end of-the shank.' Wheiigthe bit isbeing driven axially to a depth equalVv `to the height' of the enlargement ofthe shank jallof the'prim'ary blades effect their bit has bored to the desired depth, in case an oval or *other shaped" cavity isv to: -Abe (routed, the bit Yis usually propelled by the d,

operator in the proper direction,y and at j the start of any lateral movement,`tlie1pri y and the result is a' plain round holeor socket. V`After-the.

mary blade t cuts at tlhebottom, at the top, I

and .also `'forwardy-, during theiirst one#r third revolution Vof theffbitf I VlhenV the blade mreaches the starting p'ositionA, ity startsl cutting in the'next higher plane and-con-` tinues to 'cut during the next yone-third rev-v olution'. kBy this time the lprimary' blade 6a has advanced'to' the line Aand'start-s 4 ie. f, f

Vcuttin'gin the uppermost plane. It Will n .understood that the'l blades 45t-5a continue cuttingin their respective planes While blade 6 is effecting-its cut,. as described, andit the operator continuest'o propel the bit laterally the several. primary blades eut'c'on-A 'Y tinuously It will be also understood that i the bladeren-a,V owing to its location, shape, and itsvspacing fromV the intermediate blade .5?, performs the greaterV portion-jot the cuttiiig, for the reasonthat-said bladelciits in nthreedirections, Yaserqilained,` @Wing t0 Y theffactthatblade@ciits'into thepathfol-A flowed .byjblade g'l'the rlatter onlyY cuts forvvvardly."and Vat the top, and since the topy o. portion bof-blade acuts into ythe 'path' of blade 67%) the latter blade yonly cuts for- `wardly, in .order to gcoinplete the routing Work'.k The `tintedV Vend loi. the bit, being' 'farthest iero'm'the chuck is naturally subject .to g-reatergvibrationthanV the rest of the Y Vbit, and Vfor that reason blade 4a is arranged `to performa third more yWork than blade 15??,Qandvlikevvise blade Vfperiorins' a `third 5*.: .".inore `Work thanblade 6a.

This disposition and. arrangement of the cutting 4members tends tojrsteady-the'bit iviththe result that 'In Figs. (5v and 7 I have shofvvnfcutting routing and .otherxvvork `may be done with greater rapidity and"smoothness,V as Well as Without chatteringand no ise.

edges 4", 57 and 6c of the blades ground oit` atfanangle; For certainkinds of routing this 'angular arrangement enables the blades vantageous fory routing burly, as well as the tocut 4With 'a sheering or slicing stroke, Vwhich `tendsfco effect af'smoother iinish.

These angular blades are particularly ad-V g softer. andY more spongyspecies fofgWoOd,

liu

Qlike.

n Having thusA l; A'renting tool formed atoneend with ylongitudinal side cutting ribs,a portion of like red Wood, White Wood',V poplar Aand the Y described` my invention, what I claim, is

-each:.rib kbeing cutfaivayffor V.providing a'r 'grelatively -narrovv cutting.` spur, v they saidV spurs. being -A arranged to cnt in different pla-nessequentially; andvvthe combined cut#y tingY range ofthe several spurs being. substantially equal tofthelength ot said ribs. .f

l2. :A routing ltoolcomprising a longitudi-V r.one-half theynormal length 'of said edges.

cal body havinga iluted enlargement at one Vend for providinga plurality of lo'ngitudi'a.;l

y 5 5 nal equidistantly spaced 4ribslhaving similarlefss than onefh-alf'the-lengtlipf the ridges,v 130 the blades of the severaledges being arranged to out in parallel planes sequentially, @wand the paths cut merging.

Y Yby '.said Vblades Y partiallyV 3. A krouting tool comprising aieylindrifV side-cutting edges, a portion of said ribs be.n ing cut away vfor, providing routingblades of less than one-half! the normal lengthV of said side-Cutting edges, and Vthe several blades being arranged totravel .aiidfcut'in i different transverse planes.

4.' A routing tool comprising, a shank hav'- ing an enlargement-at one end', said enlargement being luted Tfor providing longitudi-V o nal ridges .havingsimilar .side-'cutting' surfaces,a portion of eachridge being cut away n for reducing the effective vcuttingedgertog less than onehalfthe .lengthpoflthe ridge, y and the cutting.edgesjofethe severa-lridges o being arrangedV in s Vdiffe'rei'it planesffgand adapted to travelfin1 parallel Ypaths` thatv overlap each other-..

5. A routing toolI comprising?1L-wineacal bodyV having a fluted en]afgungut-foriV47 y Vproviding a pluralityfoff longitudinal ribs,A

said ribs Vvhaving similar side-cutting edgesrv' and 'being' cutaway inrpart for providing.

routing blades of less thaiifonefhalfthe nOi'f mal length ofk saidk yside-cutting` edges,@the1 bladesl of-each rib being arranged .totravel the adjacent blades, and the `blade of one rib extending beyond o the .endfiofthe. body 'v 'Y one end, saiden'largement being flutedlfor providing ,equidistantly spaced :longitudinal ribs, saidribs beinggforined With similaiyv icc'Y 1 ingcut awayrat the top forproviding acut- 'i A side-cutting edges, a portionot'one rib-'be-f` vidin'g a medial cuttingbladefthe'neXtv rib 'providey ajcutting blade at'the "topbf the A rib, andfsaid .cutting biladesadaptedfto cut' rotary paths: parallel to and f overlal'ipingvVv Veach other. .f K Y i 7. Arouting tool comprising a bodyrh'avlj `tionsof the nextrib inorder being" cut` away at the'top andat the bottoni for Apro- Y in orderbeing eut avvayllx'atitsfbottomto y i imY ing an enlargement aton'e end,-said enlarge-.V

nient rbeing rfluted fori-providing similar angular longitudinal ribs, therOrreSpQnding j edges of said ribsjbe'ing sharp'.` portions of said ribs being cutaway'for providing pre-f jecting primary jcutting blades' thaty are ar. ranged. to-cuti in paralleliplanes,.the r,blade ofi-each rib adaptedto itraveluin a paththat Y overlaps thejpath' v traveled the vadj acentV 120 blade. and each ribbeing provided,ivitliraff seeondary cutting edge thatejects the chips blades? 8i-A routing to being "out, away for providingjc-utting edges Vresulting Yfrom"thejcutting bytheprimary Y y p olcomprisinga bodyfhav-L-k125.v infl'anfellgemenbatene end. the enlarge?` -inent being'fluted for providing angular 'i side-,cutting y. ridges, portions of ,Sad dgeS the cutting edge of one ridge being disposed VtraNel and out` circular paths .that liek in" `v` vat the. bottom of the enlargement, the cut parallel.'p1an`es, and the `path of the medialv y ting edge kof the next. riblbeing disposed vCutting edge overlapping the paths of the l0l midway between the top and bottom of the y adjacent cutting edges. t 5 enlargement, andthe/cutting edge of theA njtestimon'y n'dieieof `I aHXmy signathird ridge being disposed at thetop ofthe ture. Y v n enlai'geneient, said Cuttingv edges .o adaptednto -V f i j RAY LL-CARTER. 

